Rotary bit



March 28, 1933. w. c. BAILEY ROTARY BIT Filed Oct. 19, 1927 v 4 Sheets-Sheet l HTTORMEY.

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March 28,1933. w. c. BAILEY 1,902,

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Patented Mar. 28 1933 WALTER, C. BAILEY, OF NORWALK CALIFORNIA ROTARY IBI'I.

Application filed October 19, 1927. Serial No. 227,103.

My invention relates to rotary deep well drilling equipment and more particularly to rotary bits.

In the rotary system of drilling deep wells,

a hole is started in the surface of the ground and a rotary bit, mounted on the lower end of a tubular drill stem, is extended into the hole. The drill stem is now rotated and lowered gradually into the hole by suitable machinery so that the rotary bit deepens the hole. Detritus removed by the bit is raised to the surface of the ground by a circulation of rotary mud downwardly through the drill stem and upwardlybetween the drill stem and the walls of the hole. 7 There are in general use various forms of rotary bits, one of which is the disc bit. This type of bit has a pair of disc cutters rotatably mounted in offset relation on the lower end-of a bit body.

29 When the bit body is rotated, these cutters not only dig into the earth upon which the bit rests but each cutter rotates upon its own axis so that all parts of its peripheral cutting edge wear uniformly.

Owing to the limited spacein which the bit body must operate, it-has been found an exceedingly difficult matter to provide a simple mounting for the cutters of a disc bit which will stand the immense strains to which it is 33 subjected by the drilling.

It is an object of my invention to provide a rotary disc bit having a simple and extremely strong mounting for the cutters.

It is a further object of my invention to 35 provide a rotary disc bit as above described in which the cutters may be quickly removed for repair or replacement.

In my co-pcnding application for U. S.

Letters Patent upon a rotary disc bit, Serial 43 No.189,569,filed May 7, 1927, which has since developed into United States Patent No. 1,- 670,092, I show a disc bit in which the cutters are mounted upon offset bushings which are in turn mounted upon a single pin. The bushings and the pinare eccentric relative tov oach'other, and fit into openings in the bit body which are correspondingly eccentric so as to retain the bushings and pin in their r proper relative positions. This construction permits a shearing action to be set up between spacer ring forming a part of this bit;

the bushings and the body tending tovshear oil the pin.

It is a further object to provide a rotary disc bit of the character above described in which said shearing tendency is eliminated.

Another difliculty experienced in drilling certain kinds of formation, such as shale, with a disc bit is the balling up of the bit due to faulty circulation of the rotary mud.

It is another object of my invention to provide a rotary disc bit in which the balling up of the bit is efi'ectively prevented by an improved means for circulating rotary mud around the cutters.

The body of a rotary disc bit is often neces- 5 sarily somewhat larger in diameter than the drill stem to which it is attached. As the bit moves downward in the drilling operation,

the cutters form a hole ample in size to accomodate the bit body. The walls ofthe hole above the bit tend'to be mudded up, however, so that withdrawal of the bit becomes difii-cult. 1 I

,It is a further object of my invention to provide a rotary bit which may be easily 7 withdrawn upwardly through a mudded up hole.

Further objects and advantages will be mademanifest in the following description and accompanying drawings in which a preso ferred embodiment of my invention is illustrated. In the drawings:

Fig. 1 is a side elevational view of a preferred formof the bit of my invention.

Fig. 2 is a horizontal sectional view taken on the line 22 of Fig. 1.

Fig. 3 is a'fragmentary end elevational view of Fig. 1, shown partially in section to illustrate the structure of the bit.

Fig. 4 is a horizontal sectional View taken on the line 4 t of Fig. 3.

Fig. 5 is a vertical sectional viewrtaken on'theline 5-5 ofFig.4.

Fig. 6 is a perspective'view' of a'cutter mounting bushing forming a part ofthe bit shown in Fig.1.

Fig. 7 is a perspective'view showing'a' wear plate used in this bit. -i r Fig. 8 is a perspective view showing a Fig. 9 is a fragmentary perspective View illustrating the formation of the inner surface of one of the legs of the bit, shown in Fig. 1.

Fig. 10 is a side fragmentary elevational View of a modified'form of the bit of my invention.

Fig. 11 is a fragmentary end elevational view of the bit shown in Fig. 10 with parts thereof shown in section to illustrate their structure.

Fig. 12 is a horizontal sectional view taken on the line 12-12 of Fig. 10.

Fig. 13 is a vertical sectional view on the line 13-13 of Fig. 12.

Fig. 14 is a side elevational view of. another modified form of bit embodying the invention.

taken on the line 1515 of Fig. 14.

Fig. 16 is a fragmentary end elevational view of the bit shown in Fig. 14, with parts thereof shown in section to illustrate their structure.

Fig. 17 is a horizontal sectional View taken on the line 17-17 of Fig. 16.

Referring specifically to the drawings:

Fig. 1 shows a bit 20 having a body 21 provided at its upper end with a threaded pin 22 for attaching the bit to a drill stem not shown. The body 21 includes a shank portion 23 and a cutter bearing portion 24, the latter being of considerably larger diameter than the shank portion 23. The cutter. bearing body port-ion 24 includes two semi-cylindrical formations 25 which are separated by oppositely disposed vertical channels 27 and 28. Formed upon the body 21 at the juncture of the shank and cutter bearing portions thereof are longitudinal flanges 30 which border the vertical channels 27 and 28, and longitudinal flanges 31 which are disposed on opposite sides of the bit body 21 and equidistant from the adjacent flanges 30. The flanges 30 and 31, as clearly shown in Fig. 1, are formed to act as reaming blades in a manner which will be described later. 7

Provided on the body 21 is a pair of legs 33, one of which extends downwardly from each of the formations 25. The legs 33 are separated by a space 34 so that the inner surfaces 35 of the legs are parallel. Formed in the inner surfaces 35 of the legs 33 are pockets 36 which are preferably cylindrical in shape and which are disposed with their axes offset or eccentric relative to each other in a horizontal plane. Formed in the legs 33 are aligned holes 37, the axis of which intersects the axis of the bit 20. Also formed in each of the legs33 s0 asto communicate with the holes 37 are threaded locking pin openin s 38.

t is desired to rotatably mount apair of Fig. 15 is a-horizontal sectional viewtaken disc cutters 40 upon the body legs 33. Means wear late locking channels 44 formed in its perip eral surface. Formed across the end of each bushing on which the flange 43 is provided is 'a spacer locking channel 45. Formed in each of the bushings 41 with its axis parallel but eccentric relative to the axis of that bushing is a pin bore 46. One of the disc cutters 40 is adapted to rotate upon the journalled portion 42 of each of the bushings 41. After the cutter 40 has been thus disposed, a wear plate 48, which is a flat washer having a pair of'oppositely disposed lugs 49 projecting inwardly therefrom, is placed over the journalled portion 42 of the bushing 41 so that the lugs 49 extend into the wear plate locking channels 44. When the cutters, the bushings 41, and the wear plate 48 are thus assembled, the projecting end of the journalled portion 42 of each of the bushings 41 is extended into one of the pockets 36 in the legs 33. The bushings 41 are now rotated in the pockets 36 so that the pin bores 46,

which are formed in a manner to make this possible, are brought into alignment with each other and with the pin holes 37 formed in the legs 33. The spacer locking channels 45, which are formed in the now inwardly disposed faces of the bushings 41, are now parallel to each other..

Adapted to snugly fit between the inner faces of the bushings 41, sothat interlocking lugs 50 formed on the opposite faces thereof slide into the spacer locking channel 45, is a spacer 51. The spacer 51 has a central bore 52 which, when the spacer is slid to the proper position between the bushings 41, will be aligned with the pin holes 37 and the pin bores 46. The spacer 51 is preferably formed by casting, and has an annular passageway 54 formed internally therein which has an inlet opening 55 formed in the top, and a discharge port 56 at-ithe bottom. Formed in the upper end of the inlet opening 55 is a slight counterbore 57, for a purpose to be described later.

. When the parts thus far described have been positioned as indicated, an assembly pin 60 is extended through the aligned holes 37 and bores 46 and 52 so as to maintain these parts in assembly. In order to prevent the assembly pin 60 from being removed, this pin .has recesses 61 formed to open in opposite directions from opposite ends of the pin so that each recess is in alignment respectively with one of the locking pin openings 38. Screwed into the openings 38 so that their inner ends 65 extend into the recess 61 and retain the assembly pin 60 permanently in place, are locking pins 63. Formed centrally 41. The lower endof the central branch passage 69 is provided with threads 75.

In assembling the bit, a fluid conductlng pipe 76, the upper end of which has cylindri-.

cal threads adapted to fit the thread 75, is provided with a lock nut 78 and is then screwed upward into the thread 75 as far as it will go. After the assembly of the bit has been completed, however, the pipe 76 is.

screwed out of the thread 75 until the lower end thereof is tightly seated in the counter: bore .57 formed in the inlet opening of the spacer 51. The lock nut 78 is now screwed upward against the bit body 21 so as to retain the pipe 76 in this position. The bit 20 is now ready for operation.

In the operation of this bit, the bit is attached by the pin 22 to the lowest of a string of .drill pipes and is extended into the lower end of a well 80, as shown diagrammatically in Fig. 1. As the bit is lowered, the drill pipe is rotated so that the cutters 40 here into the earth and deepen the hole.

As" previously explained, considerable difliculty has been experienced in accomplishing a discharge of the rotary mud from a rotary bit in a manner to prevent balling up of the bit under. certain drilling conditions. In the operation of the bit 20, the rotary mud flows downward in the drill stem into the fluid passage 68 and is discharged from this through the pipes 71 and 76. 'The streams emitted from the pipe 71 pass on each side of the spacer 51 into the space between the cutters 40. Fluid carried by the pipe 76 enters the annular channel 54 of the spacer'51 and is discharged through the port 56 so that fluid leaving this port passes directly downward entirely preventing any possibility of the bit 20 balling up.

When the bit 20 has deepened the well the desired amount, the bit is raised until it comes into contact with a portion of the hole which has been mudded up so that the diameter of the hole is insufficient to permit the cutter bearing" portion 24 of the bit to pass upward therethrough. The a bit is now rotated and the longitudinal flanges 30 and 31 have a reaming action upon the walls of the hole so that this is enlarged to a sufficient diameter to accommodate the upward movement of the bit. Thus, not only do the longitudinal flanges 30 and 31 permit a comparatively light and strong construction but they also operate as reaming blades on the withdrawal of the bit from a hole which has been mudded up to any extent.

Referring specifically-to Fig. 4, it will be noted that, owing to the offset relation of the cutter carrying bushings 41, any tendency to rotate these bushings'in theirrespective pockets 36 would exercise a strong shearing action upon the assembling pin 60. Any tendency to rotate the bushings 41 results from the friction between the cutters40 and their respective bushings, and this friction tends torotate the bushings 41 in opposite directions. Such rotation in opposite directions, however, is entirely prevented by the interlocking of the spacer 51 with the bush ings 41. Thus, the spacer 51 not only performs the function of holding the bushings 41 in place in their respective pockets 36 and forms a discharge nozzle for. rotary mud, but also adds immensely to the strength of the cutter mounting assembly by providing independent means for preventing rotation between the two bushings 41.

Referring now to Figs. 10 to 13 inclusive, 110 indicates amodified form of bit which embodies my invention and which has a body 111 which is provided with cutter supporting legs 112 which extend downward therefrom. The legs 112 are centrally -dis-- posed on opposite sides of a central space 113 so that the inner surfaces 114 of these legs 112 are parallel.

Formed tangentially in the surfaces 114 of the legs 112 are cutter bushing pockets 115, one side 116 of which is closed, the other side 117 of which is open. The open side 117 of each of the pockets 115 is at the advancing edge of the leg 112 in which that pocket is formed. Formed in the outer surface of each of the legs 112 is a dovetail channel groove 118. Provided in each leg 112 in the upper and lower ends of the channel 118 are tapped holes 119 and 120, for a purpose to be described later.

The legs 112 also have aligned holes 121, the axis of which intersects the vertical axis of the bit 110 and lies perpendicular to the leg surfaces 114.

It is desired to mount a pair of cutters 125 upon the legs 112 and means for this purpose includes bushings 126 which have a cylindrical journalled portion 127, one end 128 of which is flattened, as clearly shown in Fig. 13, while the other end is provided with a radial flange 129. Extending through each bushing 126, parallel with but eccentric to the axis thereof, is an assembling pin bore 130. fIn assembling the bit 110, one of. the cutters 125 is placed upon each of the bushings 126, as show-n, and a wear plate in the form of a ring 132 is placed over the projecting end of the journalled portion 127 of each of the bushings 126. locking boss 133 formed therefrom, the upper and lower faces of which are disposed in continuation of the upper and lower faces of the flattened end portion 128 of the journal-led Each ring 132 has a that ring is mounted. When the cutters 125, the bushings 126, and the wear rings 132 are thus assembled, the bushings 126 are insertedfrom opposite directions inward into the space 113 so that the flattened end 128 of each bushing 126 enters the open side 117 of one of the pockets 115. The bushings 126 are of such size that when these enter the space 113 from opposite directions, the adjacent faces of the bushings 126 snugly slide upon each other so that there is practically no freedom of movement between the bushings 126 and the bit body 111. The assembling bores 130 of the bushings 126 are so formed that when the bushings 126 are forced snugly against the closed ends 116 of their respective pockets 115, the aligned holes 121 and the assembling pin bores 130 are in alignment. An assembling pin 135 is now extended through these aligned holes so as to lock the parts above-mentioned into proper assembled poretained in place by sition; The pin 135 has notches 136 formed in its opposite ends so as to open upwardly when the pin is in its place. Before the pin 135 has thus been positioned, locking blocks 137, which fit the dovetail channels 118, are slid into the upper end of these channels. Forng ed downward upon each of these blocks 137 is a lug 138 which is adapted to snugly fit into one of the notches 136. Thus, after the pin 135 is in place, the blocks 137 are moved downward so that the lugs 138, the notches 136, and the blocks 137 are then retained in this position by the insertion of a filler block 140 in the upper end of the channel 118, which is retained in place by a screw 141 which passes through the block 140 and is threadedly received one of .the holes 119.

The lower end of each channel 118 is preferably closed by a filler block 145 which is a screw 146 which passes through this block and is threadedly received in one of the holes 120. Itis thus seen that the assembly of the bit 110 is extremely simple-and that with the engagement of the assembling pin 135 by the locking lugs 138, the whole assembly is rendered exceedingly strong.

The main strain placed upon a disc bit is the resistance of the earth to the cutters. This resistance is taken up in the bit 110 by the contact of the flattened ends 128 of the bushings 126 with the closed sides 116 of the pockets 115. It is to be noted that each wear ring 132 is rigidly held against rotation by its boss 133 which extends into the open end 117 of the adjacent pocket 115.

' Referring now to Figs. 14 to 17 inclusive, 220 indicates a second modified form of bit embodying my invention. The bit 220 has a body 221 from which two legs 222 and 223 extend downward so that inner surfaces 224 thereof are parallel to each other and on opposlte sides of the space 225. Formed in the surfaces 224 of the legs 222 and 223 are shalthe leg 222 and are connected by a hole 233,

which is disposed at right angles to the holes 228 and 229 and which has counterbores 234 and 235 formed in its opposite ends. cent to counterbore 235, the hole 233 is provided with threads. Aligned respectively with these holes are upper and lower holes 236 and 237 which are formed in the leg 223. The holes 236 and 237 have a uniform diameter except at the outer ends thereof where each of these holes has an annular inwardly projecting shoulder 238.

It is desired to mount a pair of cutters 240 upon the legs 222 and 223. A means for this purpose includes a pair of bushings 24 1. Each of the bushings 241 has a cylindrical head 242 which is adapted to fit one of the shallow pockets 226 and a radial flange 243 which fits against one of the inner surfaces 224 when the head 242 is thus positioned. Extending .inward from the flange 243 is a cutter journal 244 upon which one of the cutters 240 isadapted to rotate. Each of the bushings 241 is provided with upper and lower assembling pin bores 246 and 247 which are so formed that when the bushings 241 are in place, as above described and as shown in Figs. 16 and 17, the bushings may be rotated so as to bring the bores 246 and 247 into alignment respectively with each other and so as to bring the upper holes 246- into alignment with the upper 236 and to bring the lower holes 247 into alignment with the lower leg holes 229 and 237. When the bushings 241 carrying the cutters 240- are thus positioned, they are adapted to be held snugly in their respective pockets 226 by the insertion of a spacer 250 between the bushings 241. The spacer 250 is of the shape shown in Figs. 16 and 17 and has upper and lower holes 251 and 252 which are adapted to be aligned with the respective upper and lower holes of the legs 222 and 223 and the bushings 241 which are in horizontal alignment, as above described.

With the various upper andlower holes thus aligned, upper and lower assembling pins 254 and 255 are extended through the holes 228 and 229 so that the upper pin 254 passes through all of the upper aligned holes and so that the lower pin 255 passes through all of the lower aligned holes and so thatthese pins are disposed in the position in which they are shown in Fig. 16.

When the pins 254 and 255 are thus in place, their innerends abut against the shoulders 238. Formed in the opposite ends of the pins 254 and 255, so that they will now be disposed Adj a-,

leg holes 228 andopposite the hole 233 in the leg 222, are annular channels 260'and 261. Adapted to be extended into the hole 233 so as to enter the channels 260 and 261 and lock the assembling pins 254 and 255 against removal is a locking screw 263, the head 264 ofwhich enters the counterbore 234 and abuts against the shoulders in the juncture of this counterbore and the hole 233. Adapted to engage with the threads formed at one end of the hole 233 are threads 266 formed upon the screw263. The screw 263 has a recess 27 0 formed in the shank thereof near the head 264 so that when this recess is disposed opposite one of the assembling pins 254 or 255 that pin maybe withdrawn from the bit 220; but when the recess 270 is disposed, as shown in Fig. 17, in

' other Words, at right angles to the assembling pins 254 and 255, these assembling pins are effectively locked against removal.

In finally assembling the bit before its use, the pin 263 is screwed into the hole 233 so that in its final position the-recess 270 is disposed as shown in Fig. 17 and so that the pins 254 and 255 are retained in place. The extremity 271 of the shank of the screw 263, which extends into the counterbore 235, is now riveted down so as to retain the screw 263 in its assembling pin locking position.

The bit 220, when thus assembled, presents a structure which has great strength owing "to the use of two assembling pins to unite the legs, the bushings, and the spacer of the bit. When it is desired to disassemble the bit for repairs, the screw 263 need not be entirely removed from the hole 233, but by striking upon the extremity 271 of its shank this pin may be loosened and turned so that the recess 270 is opposite one or the other of the pins 254'and 255 in succession so that these pins may be removed. That is, thescrew 263 is first turned so that the recess 270 is opposite the pin 255, whereupon this'pin is removed and thereafter the screw 263 is turned another half revolution so that the recess 270 is opposite the pin 254 to permit this assembling pin to be removed and thus efl'ect the complete disassembly of the working parts of the bit.

I claim as my'invention:

1. A rotary bit for drilling wells comprising: a drill bit bodyadapted to support a pair of cutters, there being a pair of pockets formed in said body on opposite sides of the axis thereof, said pockets being disaligned with each other, and a hole in said body which is ali ned with each of said pockets; cutter bushings adapted to fit into said pockets, there being openings in said bushings adapt-'- ed to'be aligned with-said hole in saidv body; cutters adapted to rotate upon said bushings; a locking pin adapted to extend into said body hole and into the openings in said bushings; and means disposed between and interlocking with said bushings for preventing rotation of said bushings relative to each other.

2. A rotary bit for drilling wells comprising: a drill bit body adapted to support a pair of cutters, there being a pair of pockets formed in said body on opposite sides of the axis thereof, said pockets being disaligned with each other, and a hole in said body which is'alignedv with each of said pockets; cutter bushings adapted to fit into said pockets, there being openings in said bushings adapted to be aligned with said holein said body; cutters adapted to rotate upon said bushings; a locking pin adapted to extend into said body hole and into the openings in said bushings; and a spacer disposed between and interlocking with said bushings to prevent relative rotation therebetween.

3. A combination as in claim'2 in which means is provided for supplying rotary mud to said spacer and in which said spacer has an opening which conducts said rotary mud to a suitable point of discharge.

4. A rotary bit for drilling wells compris ingza body having a pair of depending legs separated by a space, there being aligned openings formed in said legs and pockets formed in the inner surfaces of said legs eccentric relative to said openings; a pin extending intosaid openings; a pair of bushings having eccentric apertures into which said pin extends; and means for separating said bushings so that portions thereof extend into said pockets thereby preventing their rotation relative to said body, said means disposed between and interlocking with said bushings to prevent their rotation relative to each other.

5. A rotary bit for drilling wells comprising: a body having a pair of depending legs separated by a space, there being aligned openings formed in said legs and pockets formed in the inner surfaces of said legs eccentric relative to said openings; a pin extending into said openings; a pair of bush? ings having eccentric apertures into which said pin extends; a spacer for separating said bushings so that portions thereof extend into said pockets thereby preventing their rotation relative to said body, said spacer interlooking with said bushings to prevent their rotation relative to each other; and means for supplying rotary mud to said spacer, there being an opening in said spacer which conducts said mud to a suitable point of discharge.

6. A combination as in claim 5 in which said point of discharge is beneath 'said pin.

7. A rotary bit for drilling wells comprising: a drill bit body adapted to support a pair of cutters, there being a pair of pockets formed in said-body on opposite sides of the axis thereof, said pockets being disaligned '20 tending into said openings;

said hole in said. body; cutters adapted to rotate upon said bushings; a locking pin adapted to extend into said body hole and into said bushing openings; and means disposed between and interlocking with each of said bushings to prevent relative rotation therebetween.

I 8. A combination as in claim 7 in which means is provided for supplying rotary mud 10 to said interlocking bushing means and in which said interlocking means is provided with an opening to conduct said rotary mud to a point of discharge.-

9. A rotary bit for drillin Wells compris- 1 ing: a body having a pair 0i depending legs separated by a space, there being aligned openings formed'in' said legs and pockets formed in the inner surfaces of said legs eccentric relative to said openings; a pin exa pair of cutter bushings having 60081113110 apertures into which said pin extends; and means spanning the space between and separating said bushings so that portions thereof extend into said pockets to prevent rotation of said bushings relative to said body, said means interlocking with said bushings to prevent their rotation relative to each other.

10. A rotary bit for drilling wells com- '30 prising: a bod having a pair of depending legs separated y a space and having aligned openings extending ther'ethrough and pockets formed in the inner surfaces of said legs eccentric relative to said openings; a pin extending into said openings; a pair of cutter carrying bushings having eccentric apertures into which said pin extends; a spacer for separating said bushings so that portions thereof extend into said pockets to prevent their rotation relative to said body, said spacer interlocking with said bushin s to prevent their rotation relative to eac other; and means for supplying rotary mud to said spacer through an opening therein so as to conduct said mud to a point of discharge beneath said pin.

11. A rotary bit for drilling wells comprising: a drill bit bod adapted to support a pair of cutters, there eing a pair of pockets formed in said bod on oppos te sides of the axis thereof, sai vpockets being disaligned with each other, and a hole in said body aligned with each of said pockets; cutter bushings adapted to fit into said pockets,

v there being openings in said bushings adapted to be aligned with said hole in said body; cutters adapted to rotate upon said bushings; a locking pin adapted to extend into said body hole and into the openings in said bush-' 5 in s; and means disposed between and interlocking with said bushings to prevent relative rotation therebetween. I

A rota 'bit for drilling wells comprising; a dri 1 bit bod adapted to support m pair of cuttem, there eing aipair of pockets formed in saidbody on opposite sides of the axis thereof, said pockets being disaligned with each other, and a hole in said body aligned with each of said pockets; cutter bushings adapted to fit into said pockets, there being openings in said bushings adapted to be aligned with said hole in said body; cutters adapted to rotate upon said bushings; a lockingpin adapted to extend into said body hole and into the openings in said bush ngs; and means disposed between and interlocking with each of said bushings to prevent relative rotation therebetween,

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 13th day of October, 1927.

WALTER C. BAILEY. 

